The interleukin-1 genotype as a severity factor in adult periodontal disease

The oral microbial consortium's interaction with the periodontal innate defense system

The oral microbial consortium is the most characterized polymicrobial microbial community associated with the human host. Extensive sampling of both microbial and tissue samples has demonstrated that there is a strong association between the type of microbial community found in the gingival crevice and the status of innate host mediator expression. The strong clinical association between the microbial community and the innate host response in both clinically healthy and diseased tissue suggests that the oral consortium has a direct effect on periodontal tissue expression of innate defense mediators. A preliminary study in germ-free mice has demonstrated that the oral commensal consortium has direct effect on IL-1beta expression, indicating that this microbial community may contribute to the strong protective status of healthy gingival tissue. Likewise, the lipopolysaccharide composition and invasion characteristics of Porphyromonas gingivalis, an oral bacterium strongly associated with periodontitis, suggest that it may be a keystone member of the oral microbial community and facilitate a destructive change in the protective gingival innate host status.

Assessment of chromosome 19 for genetic association in severe chronic periodontitis

BACKGROUND

A genome-association study is a powerful tool for analyzing small gene effects in complex diseases such as chronic periodontitis (CP), although the cost of analysis is prohibitive. We designed a study using the DNA pooling method, which could be a breakthrough in lowering such costs. This study was conducted to assess the genetic association in severe CP in a Japanese population.

METHODS

We adopted a DNA pooling method by genotyping 454 densely spaced microsatellite (MS) markers in chromosome 19 as a pilot study, with the possibility of future use in a whole-genome study. This can reduce the high cost and technical burden, which is generally unavoidable in a genomic association study. Pooled DNA samples from 300 case subjects, 300 control subjects, and 200 systemically healthy subjects were screened by genotyping MS markers. The case-control association in the candidate region was analyzed by individual typing of MS and single nucleotide polymorphisms (SNPs).

RESULTS

The single MS marker allele 17 of 1902G31 was isolated in association with severe CP (P = 0.0012 for 2 x 2; P <0.046 for 2 x m, where m refers to the number of polymorphic alleles observed in a population). No other SNP or MS polymorphism hypothesized to affect biologic functions in the critical region was found in the linkage disequilibrium block analysis.

CONCLUSIONS

We efficiently isolated the susceptible locus for severe CP in chromosome 19 and identified a useful marker to evaluate the risk for disease. This approach can be applied to a whole-genome study in severe CP.

Periodontal disease status in gullah african americans with type 2 diabetes living in South Carolina

BACKGROUND

African Americans have a disproportionate burden of diabetes. Gullah African Americans are the most genetically homogeneous population of African descent in the United States, with an estimated European admixture of only 3.5%. This study assessed the previously unknown prevalence of periodontal disease among a sample of Gullah African Americans with diabetes and investigated the association between diabetes control and the presence of periodontal disease.

METHODS

Two hundred thirty-five Gullah African Americans with type 2 diabetes were included. Diabetes control was assessed by percentage of glycosylated hemoglobin (HbA1c) and divided into three categories: well controlled, <7%; moderately controlled, 7% to 8.5%; and poorly controlled, >8.5%. Participants were categorized as healthy (no clinical attachment loss [AL] or bleeding on probing) or as having early periodontitis (clinical AL > or =1 mm in at least two teeth), moderate periodontitis (three sites with clinical AL > or =4 mm and at least two sites with probing depth [PD] > or =3 mm), or severe periodontitis (clinical AL > or =6 mm in at least two teeth and PD > or =5 mm in at least one site). Observed prevalences of periodontitis were compared to rates reported for the National Health and Nutrition Examination Survey (NHANES) studies.

RESULTS

All subjects had evidence of periodontal disease: 70.6% had moderate periodontitis and 28.5% had severe disease. Diabetes control was not associated with periodontal disease. The periodontal disease proportions were significantly higher than the reported national prevalence of 10.6% among African Americans without diabetes.

CONCLUSION

Our sample of Gullah African Americans with type 2 diabetes exhibited a higher prevalence of periodontal disease compared to African Americans, with and without diabetes, as reported in NHANES III and NHANES 1999-2000.

Periodontal infectogenomics

Multicellular creatures consist of a symbiosis between the host and its colonizing bacteria. The oral cavity may contain as many as 19,000 bacterial phylotypes, while each individual presents a proportion of these microbes. Infectogenomics studies the interaction between host genetic variations and composition of the microbiota. This review introduces the concept of periodontal infectogenomics, defined as the relationship between host genetic factors and the composition of the subgingival microbiota. In particular, the evidence for the effect of genetic variants in neutrophil and cytokine genes and the presence of periodontopathogenic bacteria will be discussed. The influence of genetic factors may affect clearance or persistence of pathogenic bacteria subgingivally, therefore increasing the risk for the development of common pathogenic conditions such as gingivitis and periodontitis, leading to early tooth loss. Mechanisms of interaction between genetic and microbiological factors and prospects for future studies will be discussed.

Implications of cytokine gene polymorphisms on the orchestration of the immune response: lessons learned from oral diseases

Over the past 10 years, a plethora of information concerning the influence of gene polymorphisms on cytokine expression has been made available in the literature. Significant contribution to this field has come from studies of oral diseases, one of the widest spread health problems in the world, affecting hundreds of millions worldwide. Here we will discuss the importance of studies of gene polymorphism towards the identification of susceptible groups or prognostic indicators of oral disease. Additionally, we will highlight the differences in data obtained from genetically diverse populations and review the application of cytokine gene polymorphisms studies in oral diseases in autoimmune processes and parasitic infections.

IL1A alleles associate with a virological response to antiretroviral therapy in HIV patients beginning therapy with advanced disease

Among Australians treated for advanced HIV disease, a suboptimal virological response was associated with allele 2 at interleukin 1 alpha (IL1A)-889 and IL1A+4845. This is confirmed and investigated using patients from AIDS Clinical Trials Group study 384 (n=532). Among non-African-American patients with CD4 T-cell count of< or = 100 cells/microl at baseline, IL1A+4845(*)TT was associated with poor virological outcome (P=0.03). Differences were smaller with higher baseline CD4 T-cell counts. IL1A-889 and IL1A+4845 were not in linkage disequilibrium in African-American patients, and IL1A+4845(*)T did not affect outcome.

Initial comparison of proteomic profiles of whole unstimulated saliva obtained from generalized aggressive periodontitis patients and healthy control subjects

BACKGROUND AND OBJECTIVE

Salivary proteomics technology can be used to evaluate the disease progression of periodontitis and the systemic screening of proteomes of saliva from subjects with aggressive periodontitis has not been available. The objective of this preliminary study was to compare the proteomic profile of whole unstimulated saliva of subjects with generalized aggressive periodontitis (GAgP) with that of healthy volunteers to identify proteins, the levels of which were significantly altered between the two groups.

MATERIAL AND METHODS

Whole unstimulated saliva was obtained from five subjects with GAgP and five healthy subjects, and proteins were separated using two-dimensional gel electrophoresis. Proteins, the levels of which were significantly different between the two groups, were identified by computer image analyses and subsequent electrospray ionization tandem mass spectrometry.

RESULTS

Eleven proteins that exhibited a different level in the GAgP group vs. the control group were identified. Compared with whole saliva of healthy control subjects, the levels of serum albumin, immunoglobulin (Ig) gamma2 chain C region, Ig alpha2 chain C region, vitamin D-binding protein, salivary alpha-amylase and zinc-alpha2 glycoprotein were increased in whole unstimulated saliva of GAgP subjects, while those of lactotransferrin, elongation factor 2, 14-3-3 sigma, short palate, lung and nasal epithelium carcinoma-associated protein 2 precursor and carbonic anhydrase 6 were decreased.

CONCLUSION

Comparison of the proteomic profile of whole unstimulated saliva of GAgP subjects with that of healthy control subjects revealed at least 11 differential proteins. The approach applied herein might be helpful to aid understanding of the etiology of GAgP.

Matrix metalloproteinase-1 polymorphism is associated with persistent airway obstruction in asthma in the Taiwanese population

BACKGROUND AND OBJECTIVE

Overexpression of matrix metalloproteinase (MMP)-1 has been demonstrated in asthma, and MMP polymorphisms are known to enhance disease susceptibility. We investigated whether MMP-1 polymorphism is associated with persistent airway obstruction in asthma in the Taiwanese population.

METHODS

A total of 131 unrelated Taiwanese subjects were enrolled, age-matched, and divided as follows: (1) those who had asthma with persistent airway obstruction with forced expiratory volume in 1 second (FEV(1)) and FEV(1)/forced vital capacity (FVC) values less than 75% predicted (n = 41); (2) those with asthma without airway obstruction with FEV(1) and FEV(1)/FVC values > or = 75% predicted (n = 47); and (3) normal control subjects (n = 43). All were genotyped for the 1G/2G polymorphism of MMP-1 promoter (-1607 bp).

RESULTS

1G genotypes of MMP-1 containing at least one 1G allele were found in asthmatic patients with persistent airway obstruction (OR = 3.696, 95% CI: 1.489-9.173, p = 0.027), but not in asthmatic patients without airway obstruction (OR = 2.065, 95% CI: 0.890-4.790, p = 0.091) when compared with homozygous 2G (2G/2G). The heterozygous 1G genotype (1G/2G) was more associated with persistent airway obstruction than homozygous 2G (2G/2G) (OR: 4.727, 95% CI: 1.759-12.703, p = 0.012). The adjusted risk estimate of 1G genotypes for asthmatics with persistent airway obstruction was 4.416 (95% CI: 1.651-11.812, p = 0.003).

CONCLUSION

1G genotypes of MMP-1 polymorphism are associated with asthma with persistent airway obstruction, and the heterozygous 1G genotype (1G/2G) poses the most susceptibility to persistent airway obstruction in asthma.

Association of the composite IL-1 genotype with peri-implantitis: a systematic review

OBJECTIVE

Cytokine gene polymorphisms may modulate the host response to the bacterial challenge and influence susceptibility to peri-implantitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A (-889) and in IL-1B (+3953), and peri-implantitis.

MATERIAL AND METHODS

An electronic search in the National Library of Medicine-computerized bibliographic database MEDLINE and a manual search were performed. The search was conducted for longitudinal clinical trials comparing progression of peri-implantitis in IL-1 genotype positive (carrying allele 2) with IL-1 genotype negative (not carrying allele 2) subjects. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 44 titles of which two longitudinal publications were included.

CONCLUSION

Based on the findings from this study, there is not enough evidence to support or refute an association between the IL-1 genotype status and peri-implantitis. Systematic genetic testing for the assessment of the risk of peri-implantitis cannot be recommended as a standard of care at this time.

Family-based association analysis of S100A8 genetic polymorphisms with aggressive periodontitis

BACKGROUND AND OBJECTIVE

It is known that S100A8, a member of the S100 calcium-binding protein family, is associated with inflammatory diseases, including periodontitis. Our previous population-based study found an association between two polymorphisms, rs3795391 (A > G) and rs3806232 (A > G), in the upstream region of the S100A8 gene and aggressive periodontitis (AgP) in Chinese people. Based on those results, this investigation set out to analyze and corroborate whether the association also exists within families.

MATERIAL AND METHODS

Two hundred and four subjects from 73 nuclear families were recruited. All probands and their relatives were diagnosed according to the 1999 classification of periodontal diseases. Anticoagulated peripheral blood samples were collected from all the subjects, and DNA was extracted. The two single nucleotide polymorphisms (SNPs; rs3795391 and rs3806232) were detected and analyzed by standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Analysis of genotype/allele was performed by Family-Based Association Test (FBAT) software ( http://www.biostat.harvard.edu/~fbat/default.html).

RESULTS

There was a statistically significant association of the SNP rs3795391 with AgP in the additive genetic model (chi(2) = 3.9836, d.f. = 1, p = 0.0459). Allele A showed significantly preferential transmission to the AgP affected individuals (Z = 1.996, p = 0.0459). The other SNP, rs3806232, showed no significant results in all models.

CONCLUSIONS

This family-based association study supports the previous findings that SNP rs3795391 (A > G) of the S100A8 gene might contribute to AgP susceptibility. This is, to our knowledge, the first investigation about AgP using FBAT in genetic analysis.

Association between periodontitis and common variants in the promoter of the interleukin-6 gene

We recently reported an association between interleukin-6 (IL6) polymorphisms (SNPs) and haplotypes and aggressive periodontitis (AgP). The aim of this study was to investigate this association in a larger cohort of subjects, affected by either aggressive or chronic periodontitis. Five IL6 SNPs were analyzed in 765 subjects (167 generalized aggressive periodontitis, 57 localized aggressive, 310 chronic periodontitis and 231 periodontally healthy). Among Caucasians (n=454) there were moderate associations for -1363T allele (p=0.011) and for -174GG and -1363GG genotypes with diagnosis of periodontitis (respectively, p=0.044, OR=1.6, 95% CI=1.0-2.4, and p=0.017, OR=1.8, 95% CI=1.1-2.8, adjusted for age, gender and smoking). Haplotypes containing the -174G>C, -1363G>T and -1480C>G polymorphisms were associated with diagnosis of periodontitis (p=0.02). Subgroup analysis by disease phenotype showed associations for the localized AgP (LAgP) group and -1480C>G and -6106A>T SNPs (p=0.007 and 0.010, respectively). Among Caucasians the genotypes IL6 -1480 CC and -6106 TT increased the adjusted OR for LAgP (OR=3.09 and 2.27, respectively). This study supports the hypothesis that IL6 polymorphisms and haplotypes are moderately associated with periodontitis, possibly acting through influencing tissue levels of IL6. This association is stronger for LAgP than for other periodontal disease phenotypes.

Evidence-based curriculum reform: the Kentucky Experience

Evidence-based health care seeks to base clinical practice and decision-making on best evidence, while allowing for modifications because of patient preferences and individual clinical situations. Dentistry has been slow to embrace this discipline, but this is changing. In the Graduate Periodontology Program (GPP) of the University of Kentucky, an evidence-based clinical curriculum was implemented in 2004. The tools of evidence-based health care (EBHC) were used to create evidence-based protocols to guide clinical decision-making by faculty and residents. The program was largely successful, although certain challenges were encountered. As a result of the positive experience with the GPP, the college is implementing a wider program in which evidence-based protocols will form the basis for all patient care and clinical education in the predoctoral clinics. A primary component of this is a computerized risk assessment tool that will aid in clinical decision-making. Surveys of alumni of the periodontal graduate program show that the EBHC program has been effective in changing practice patterns, and similar follow-up studies are planned to assess the effectiveness of the predoctoral EBHC program.

Mapping the pathogenesis of periodontitis: a new look

Chronic adult periodontitis is a bacterially induced chronic inflammatory disease that destroys the connective tissue and bone that support teeth. Concepts of the specific mechanisms involved in the disease have evolved with new technologies and knowledge. Histopathologic observations of diseased human tissues were used previously to speculate on the causes of periodontitis and to describe models of pathogenesis. Experimental evidence later emerged to implicate bacterial plaque deposits as the primary factor initiating periodontitis. At the same time, specific bacteria and immunoinflammatory mechanisms were differentially implicated in the disease. In the mid-1990s, early insights about complex diseases, such as periodontitis, led to new conceptual models of the pathogenesis of periodontitis. Those models included the bacterial activation of immunoinflammatory mechanisms, some of which targeted control of the bacterial challenge and others that had adverse effects on bone and connective tissue remodeling. Such models also acknowledged that different environmental and genetic factors modified the clinical phenotype of periodontal disease. However, the models did not capture the dynamic nature of the biochemical processes, i.e., that innate differences among individuals and changes in environmental factors may accelerate biochemical changes or dampen that shift. With emerging genomic, proteomic, and metabolomic data and systems biology tools for interpreting data, it is now possible to begin describing the basic elements of a new model of pathogenesis. Such a model incorporates gene, protein, and metabolite data into dynamic biologic networks that include disease-initiating and -resolving mechanisms. This type of model has a multilevel framework in which the biochemical networks that are regulated by innate and environmental factors can be described and the interrelatedness of networks can be captured. New models in the next few years will be merely frameworks for integrating key knowledge as it becomes available from the "-omics" technologies. However, it is possible to describe some of the key elements of the new models and discuss distinctions between the new and older models. It is hoped that improved conceptual models of pathogenesis will assist in focusing new research and speed the translation of new data into practical applications.

TLR4 and IL-18 gene variants in aggressive periodontitis

AIM

We aimed to assess the association of different genotypes with increased aggressive periodontitis susceptibility by studying functional relevant variants in the pathogen-recognition receptor Toll-like receptor 4 (TLR4) and variants in the promoter region of the pro-inflammatory cytokine interleukin-18 (IL-18).

MATERIAL AND METHODS

One hundred and eleven patients with aggressive periodontitis and 80 periodontally healthy controls were genotyped for four functional variants in the TLR4 gene (c.896A>G and c.1196C>T) and in the IL-18 promoter (c.-368G>C and c.-838C>A). The genotype and allele frequencies, as well as the frequency of combined genotypes were compared between study groups.

RESULTS

There were no statistical differences in genotype and allele frequencies within the four variants between the groups. All study subjects were further classified into carriers and non-carriers of at least one variant of both genes. The logistic regression analysis adjusted for gender and smoking showed no association between carrier status of at least one variant of both genes and periodontal status (OR=1.41, 95% CI: 0.43-4.70).

CONCLUSIONS

Our results reject the hypothesis that functionally relevant IL-18 and TLR4 gene mutations have a major effect on aggressive periodontitis susceptibility alone or in combination.

Relationship between the gingival sulcus depth and interleukin-1 isoform concentrations within the adjacent gingival tissue

BACKGROUND AND OBJECTIVE

While there is substantial information concerning the concentrations of interleukin-1 isoforms within gingival crevicular fluid, there is little information concerning their concentrations within either normal or diseased gingival tissues. Therefore, the aim of this study was to evaluate the relationship between the concentrations of gingival interleukin-1 isoforms and the adjacent sulcular depth.

MATERIAL AND METHODS

Interdental gingival papillae were excised and grouped based on adjacent pocket depth and the presence of bleeding on probing. Gingiva adjacent to a sulcus of < or = 3 mm without bleeding on probing were classified as 'normal'; gingiva adjacent to a 3-mm sulcus with bleeding on probing were classified as 'diseased-slight'; gingiva adjacent to a 4-6-mm sulcus featuring bleeding on probing were classified as 'diseased-moderate'; and gingiva adjacent to a sulcus of > 6 mm featuring bleeding on probing were classified as 'diseased-severe'. Tissues were solublized and the concentrations of interleukin-1beta, interleukin-1alpha, interleukin-1 receptor antagonist and interleukin-6 were assessed by enzyme-linked immunosorbent assay. Data were compared by factorial analysis of variance, the post-hoc Tukey test and the Pearson's correlation test.

RESULTS

Gingival concentrations of interleukin-6, interleukin-1 receptor antagonist, interleukin-1alpha- and interleukin-1beta were significantly greater at diseased-severe sites than at normal, diseased-slight, or diseased-moderate sites (p < 0.05); the gingival concentrations of interleukin-1 receptor antagonist and interleukin-1alpha were significantly greater at diseased-severe than at diseased-moderate sites (p < 0.05). Interleukin-1 receptor antagonist concentrations were significantly correlated with both interleukin-1alpha and interleukin-1beta concentrations. The ratios of concentrations of the interleukin-1 isoforms were different at the various stages of inflammation.

CONCLUSION

Our data indicated a progressive increase in gingival concentrations of interleukin-1 isoforms with increased adjacent sulcular depth. However, within 'diseased' tissues, the proportional concentrations of interleukin-1alpha and -beta to interleukin-1 receptor antagonist were lowest within diseased-severe tissues.

Mannose-binding lectin gene polymorphisms in relation to periodontitis

AIM

To investigate the correlation of six functional polymorphisms in the MBL gene with MBL plasma levels in relation to periodontitis.

MATERIAL AND METHODS

A total of 92 periodontitis patients and 70 controls, all of Caucasian origin, were included. Patients and controls were genotyped for the L/H, X/Y, P/Q, A/D, A/B and A/C polymorphisms. Distributions of genotypes, rate of allele carriage and allele frequencies were compared between patients and controls. Patients and controls were subdivided in groups of genotypes. Plasma MBL levels were compared between different genotype groups.

RESULTS

On the basis of genotyping, three phenotypes with regard to mannose-binding lectin (MBL) production were distinguished: high-producers, low-producers and deficient subjects. No differences in the genotype frequencies were observed between patients and controls. Within patients and controls, subjects with the high-producing genotypes had significantly higher MBL plasma levels than low-producers and deficient subjects (p<0.001). Plasma MBL was higher in low-producer patients compared with low-producer controls (p(adjusted)=0.021).

CONCLUSION

No association could be observed between MBL gene polymorphisms and susceptibility to periodontitis in Caucasians. However, now that genotyping could distinguish the low producing and deficient subjects from the high-producers, it was observed, for the first time, that MBL acts as a weak acute-phase protein in periodontitis.

Polymorphisms in the interleukin-1 (IL1) gene cluster are not associated with aggressive periodontitis in a large Caucasian population

Polymorphisms in the interleukin-1 (IL1) gene have been suggested to influence transcription of IL1A (interleukin-1alpha) and IL1B (interleukin-1beta) and thereby the pathophysiology of periodontitis. This case-control association study on 415 northern European Caucasian patients with aggressive periodontitis (AgP) and 874 healthy controls was conducted to examine 10 single-nucleotide polymorphisms (SNPs) in the genes of the IL1 cluster for association with IL1A, IL1B, CKAP2L (cytoskeleton-associated protein 2-like), and IL1RN (IL-1 receptor antagonist). The results do not support an association between variants in the IL1 gene cluster and AgP. This case-control study had at least 95% power to detect genuine associations with variants carrying relative risks of at least 1.5 for heterozygous carriers and 2.25 for homozygous carriers. Previous reports of an association between IL1 promoter SNPs and periodontitis might reflect subpopulation effects and have to be interpreted with care.

Analysis of the association of polymorphism in the osteoprotegerin gene with susceptibility to chronic kidney disease and periodontitis

BACKGROUND AND OBJECTIVE

Chronic kidney disease (CKD) is a complex disorder, which results in several complications involving disturbance of mineral metabolism. Periodontal disease is an infectious disease that appears to be an important cause of systemic inflammation in CKD patients. Periodontal disease is characterized by clinical attachment loss (CAL) caused by alveolar bone resorption around teeth, which may lead to tooth loss. Osteoprotegerin (OPG) is a key regulator of osteoclastogenesis. Polymorphisms are the main source of genetic variation, and single nucleotide polymorphisms (SNPs) have been reported as major modulators of disease susceptibility. The aim of this study was to investigate the association of a polymorphism located at position -223 in the untranslated region of the OPG gene, previously known as -950, with susceptibility to CKD and periodontal disease.

MATERIAL AND METHODS

A sample of 224 subjects without and with CKD (in hemodialysis) was divided into groups with and without periodontal disease. The OPG polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

No association was found between the studied OPG polymorphism and susceptibility to CKD or periodontal disease.

CONCLUSION

It was concluded that polymorphism OPG-223 (C/T) was not associated with CKD and periodontal disease in a Brazilian population. Studies on other polymorphisms in this and other genes of the host response could help to clarify the involvement of bone metabolism mediators in the susceptibility to CKD and periodontal disease.

Association of interleukin-1 receptor antagonist +2018 gene polymorphism with Japanese chronic periodontitis patients using a novel genotyping method

Genetic variants at multiple loci have been shown to be associated with periodontitis risk. In this study, we have focused on nine functional gene polymorphisms encoding immunoregulation-related molecules such as cytokines (interleukin-1 (IL-1), transforming growth factor-beta1 (TGF-beta1)) and cell surface receptors (immunoglobulin G and A Fc receptors (Fc gamma R and Fc alpha R)). In total, 113 Japanese patients with chronic periodontitis (CP) and 108 race-matched healthy controls were genotyped with the modified serial invasive signal amplification reaction. There was a significant difference in the distribution of IL-1 receptor antagonist (RN) +2018 T/C allele between the patient and control groups, with enrichment of the +2018 C in controls (P = 0.021, odds ratio = 0.38). An increased frequency of the IL-1 haplotype comprising IL-1A +4845 G, IL-1B -31 C, and IL-1RN +2018 C was observed in controls (P = 0.004). Moreover, a multivariate logistic regression analysis revealed that subjects with IL-1RN +2018 C allele were less likely to have CP (P = 0.016, odds ratio = 0.29). These findings document the association of IL-1RN +2018 C with reduced susceptibility to CP in the Japanese.

An interleukin-1beta (IL-1beta) single-nucleotide polymorphism at position 3954 and red complex periodontopathogens independently and additively modulate the levels of IL-1beta in diseased periodontal tissues

Inflammatory cytokines such as interleukin-1beta (IL-1beta) are involved in the pathogenesis of periodontal diseases. A high individual variation in the levels of IL-1beta mRNA has been verified, which is possibly determined by genetic polymorphisms and/or by the presence of periodontopathogens such as Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans. In this study, we investigated the role of an IL-1beta promoter single-nucleotide polymorphism at position 3954 [IL-1beta(3954) SNP] and the presence of the periodontopathogens in the determination of the IL-1beta levels in the periodontal tissues of nonsmoking chronic periodontitis (CP) patients (n = 117) and control (C) subjects (n = 175) and the possible correlations with the clinical parameters of the disease. IL-1beta(3954) SNP was investigated by restriction fragment length polymorphism, while the IL-1beta levels and the presence of the periodontopathogens were determined by real-time PCR. Similar frequencies of IL-1beta(3954) SNP were found in the C and CP groups, in spite of a trend toward a higher incidence of T alleles in the CP group. The IL-1beta(3954) SNP CT and TT genotypes, as well as P. gingivalis, T. forsythia, and T. denticola, were associated with higher IL-1beta levels and with higher values of the clinical parameters of disease severity. Concomitant analyses demonstrate that IL-1beta(3954) and the red complex periodontopathogens were found to independently and additively modulate the levels of IL-1beta in periodontal tissues. Similarly, the concurrent presence of both factors was associated with increased scores of disease severity. IL-1beta(3954) genotypes and red complex periodontopathogens, individually and additively, modulate the levels of IL-1beta in the diseased tissues of nonsmoking CP patients and, consequently, are potentially involved in the determination of the disease outcome.

Comparison of levels of inflammatory mediators IL-1beta and betaG in gingival crevicular fluid from molars, premolars, and incisors during rapid palatal expansion

INTRODUCTION

Previously, we reported fluctuation of the levels of the inflammatory mediators interleukin-1beta (IotaL-1beta) and beta-glucuronidase (betaG) in gingival crevicular fluid (GCF) from the maxillary first molars in adolescents undergoing rapid palatal expansion. In this study, we compared the responses of IL-1beta and betaG in the GCF of the maxillary first molars, first premolars, and central incisors during palatal expansion at the same patients.

METHODS

Nine patients requiring palatal expansion were selected at the postdoctoral orthodontic clinic at Columbia University College of Dental Medicine. Each patient received periodontal prophylaxis and instructions in proper home care including rinsing with chlorhexidine. Four weeks after periodontal prophylaxis, a modified hyrax appliance was placed. The jackscrew was activated twice daily until the appropriate expansion was achieved. GCF samples were collected before and after periodontal prophylaxis and during passive wearing of the appliance, active orthodontic treatment, and retention. Fluid samples were collected with filter paper strips and analyzed by ELISA and time-dependent fluorometry for IL-1beta and betaG, respectively. The values recorded after periodontal prophylaxis were used as the baseline. Paired t tests were used to compare mediator levels at baseline with the levels obtained at each subsequent observation.

RESULTS

The results validate that IL-1beta and betaG are present in the GCF of adolescents, and, although their level decreases after a strict regimen of plaque control, it increases during orthodontic or orthopedic movement. Moreover, this study demonstrates that both heavy and light forces evoke increased levels of IL-1beta and betaG, stronger forces cause higher levels of inflammatory mediators, and both IL-1beta and betaG respond to direct and indirect application of mechanical force to teeth.

CONCLUSIONS

This investigation corroborates previous findings that an inflammatory process occurs during application of mechanical force to teeth. Although this inflammation is considered relatively aseptic, additional inflammation, such as that induced by plaque accumulation, must be avoided during orthodontic or orthopedic treatment.

The proteomes of human parotid and submandibular/sublingual gland salivas collected as the ductal secretions

Saliva is a body fluid with important functions in oral and general health. A consortium of three research groups catalogued the proteins in human saliva collected as the ductal secretions: 1166 identifications--914 in parotid and 917 in submandibular/sublingual saliva--were made. The results showed that a high proportion of proteins that are found in plasma and/or tears are also present in saliva along with unique components. The proteins identified are involved in numerous molecular processes ranging from structural functions to enzymatic/catalytic activities. As expected, the majority mapped to the extracellular and secretory compartments. An immunoblot approach was used to validate the presence in saliva of a subset of the proteins identified by mass spectrometric approaches. These experiments focused on novel constituents and proteins for which the peptide evidence was relatively weak. Ultimately, information derived from the work reported here and related published studies can be used to translate blood-based clinical laboratory tests into a format that utilizes saliva. Additionally, a catalogue of the salivary proteome of healthy individuals allows future analyses of salivary samples from individuals with oral and systemic diseases, with the goal of identifying biomarkers with diagnostic and/or prognostic value for these conditions; another possibility is the discovery of therapeutic targets.

Interleukin-4 (C-590T) and interferon-gamma (G5644A) gene polymorphisms in patients with periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is a multifactorial disease and immunologic and genetic factors have an important role in its pathogenesis. Mutation in the promoter regions of the interleukin-4 and interferon-gamma genes has been reported to modify the protein expression. The objective of this study was to evaluate the possible role of interleukin-4 (C-590T) and interferon-gamma (G5644A) polymorphisms in the susceptibility to periodontitis.

MATERIAL AND METHODS

In this case-control study, 53 patients (36 women and 17 men), comprising 27 patients with aggressive periodontitis and 26 patients with chronic periodontitis, and 56 healthy volunteers, were enrolled. DNA was isolated from all subjects, and the polymerase chain reaction-sequence specific primer method was used to study the interleukin-4 (C-590T) and interferon-gamma (G5644A) gene polymorphisms.

RESULTS

Our results showed no significant difference in the allele and genotype frequencies of interleukin-4 (C-590T) and interferon-gamma (G5644A) gene polymorphisms between patients with periodontal disease and controls.

CONCLUSION

The results suggest that the interleukin-4 (C-590T) and interferon-gamma (G5644A) gene polymorphisms may not be associated with the susceptibility of Iranian individuals to periodontitis.

Maternal periodontitis and adverse pregnancy outcomes

OBJECTIVES

Maternal periodontal diseases have been associated with increased risk of preterm birth and restricted fetal growth among relatively low socioeconomic groups. Whether the association can be generalized to middle-class populations remains uncertain. We evaluated periodontitis in relation to preterm birth (<37 weeks' gestation) and small-for-gestational-age (SGA, birth weight below the 10th percentile of birth weight for gestational age) among a group of medically insured women.

METHODS

We conducted a prospective study among participants of Project Viva, a US cohort study of pregnant women and their offspring from 1999 to 2002. Pregnancy outcomes were obtained from medical records. Self-reported periodontitis was assessed during the second trimester of pregnancy, and validated against radiographs. Logistic regression analyses were employed to evaluate the association of periodontitis with pregnancy outcomes adjusted for age, race/ethnicity, smoking status, income, frequency of dental check-ups, prepregnancy body mass index, pregnancy weight gain, gravidity, prior history of preterm birth and history of genitourinary infection.

RESULTS

Of the 1635 women, 72.7% were Caucasian, 65.0% had annual household income >$70 000, 3.8% reported having periodontitis, 6.4% delivered preterm, 5.4% delivered SGA babies, and 11.0% had poor pregnancy outcome (either preterm birth or SGA). The odds ratio (OR) associated with periodontitis was 1.74 (95% CI 0.65-4.66) for preterm delivery and 2.11 (95% CI 0.76-5.86) for SGA individually. When preterm delivery and/or SGA were combined, the OR was 2.26 (95% CI 1.05-4.85) relating periodontitis with poor pregnancy outcome.

CONCLUSION

Within the limitations of the study, the results suggest that periodontitis is an independent risk factor for poor pregnancy outcome among middle-class women.

Reliability of findings around healthy implants in association with oral hygiene measures: a clinical, microbiological, and immunological follow-up in edentulous patients

OBJECTIVES

To assess the performance of clinical, microbiological, and immunological diagnosis of peri-implant health and the influence of professional hygiene measures on them.

MATERIAL AND METHODS

Twenty-one edentulous patients with oral implants supporting a lower overdenture were followed up over 3 months beginning 1 week before their annual recall visit. Hygiene scores, probing depth, bleeding on probing (BOP), implant stability, gingival crevicular fluid (GCF) volume, sulcular interleukin-1beta (IL-1beta) and prostaglandin E2 (PGE2) concentrations, and relative concentrations of five bacterial species (polymerase chain reaction) were investigated. Measurement variation was assessed as a function of (a) intra- and (b) inter-examiner reliability, (c) inter-implant variation in each patient, (d) time, and (e) effect of hygiene measures by accuracy, repeatability, reproducibility, and visualization with the Bland and Altman Plot.

RESULTS

Measurement means and accuracy (in parentheses) were as follows: GCF volume 1.5 microl (1.5), Interleukin-1beta 8 ng/ml (26), PGE2 63 ng/ml (185), bacteria sum score 0.2 (0.7), plaque score 1 (1), BOP score 0 (1), Periotest value -4 (3), resonance frequency analysis ISQ 66 (11), and pocket probing depth 2.3 mm (0.7). No finding exhibited any statistically significant measurement variation as explained by accuracy, repeatability, or reproducibility. Bland and Altman Plots revealed insufficient agreement for replicated BOP assessments. A short post-treatment reduction in plaque and BOP scores was visually apparent. Still, professional oral hygiene measures exerted no sustained influence on the clinical and biochemical appearance of the peri-implant tissues.

CONCLUSION

All findings except BOP showed statistically acceptable repeatability and moderate vulnerability to influences present 'chairside' in clinical practice.